Study on interfacial interactions and optoelectronic properties of MEH-PPV/SnO₂ hetero-structure

Abstract

The exciton dynamics in nanocomposites of tin oxide (SnO2) nanoparticles with a conjugated polymer (poly (2-methoxy-5-(2’-ethylhexyloxy) 1,4-phenylenevinylene) (MEH-PPV) have been investigated by steady-state, time-resolved photoluminescence (PL) spectroscopy and cyclic voltammetry analysis. SnO2 is an air-stable, optically transparent, electrically conductive deep valance band metal oxide which is suitable as an electron-accepting material in organic photovoltaics (OPVs). Results reveals that SnO2 is an efficiency electron-accepting material in comparison with titanium dioxide (TiO2) nanoparticles. Efficiency charge separation takes places at SnO2/MEH-PPV interfaces when the polymer is excited, leading to enhancement in quenching of photoluminescence efficiency (10 %) and shortening of the measured PL lifetime. In addition, the reduction in recombination rate of MEH-PPV/SnO2 nanocomposite show that the incorporation of nanoparticles in the polymer chain reduce disorder in polymer chain. The blue-shift in the absorbance and emission maxima denotes that the process of in-situ polymerization resulted in shortening in conjugation of polymer chain. The electrochemical analysis for MEH-PPV/SnO2 nanocomposites shows increase in current density compared to MEH-PPV/TiO2 and pristine MEH-PPV. Moreover, the PL degradation experiments showed that MEH-PPV/SnO2 exhibited enhanced stability. MEH-PPV/SnO2 film attained 50% of the original intensity in ~ 10 days, while pristine MEH-PPV and MEH-PPV/TiO2 exhibited half-life of ~ 5 days when exposed to an ambient environment. The effect of TiO2 nanoparticles to stabilize MEH-PPV is though less important than that of SnO2. Thus MEH-PPV/SnO2 nanocomposite with enhanced absorbance, conductivity, stability and low bandgap formed an effective type-II band structure suitable for the photovoltaic active layer.

Structural and Morphological Characterization of MEH-PPV/Ag Composite

“…C=O stretching mode corresponds to peaks at 1643 cm -1 (conjugation of an aldehyde with two aromatic rings). These results support M. Ibrahim and others' position [47]. C=C aromatic ring corresponds to the peaks at 1577 cm -1 .…”

“…The fascination with conjugated polymers stems from their exceptional mix of characteristics [42][43][44][45][46]. The polymer found in lightemitting polymers conducts electricity when subjected to a voltage [46,47]. Others researchers in 2022 focused on manufacturing certain thin films used gas detectors to improve their quality.…”

Exciton Dynamics of MEH‐PPV polymer based Nanocomposites: Effect of Molecular Orbital Energy Levels of Nanoparticles**

“…The PL intensity of polymeric solutions was compared with the PL intensity of fluorescein dissolved in 0.1 M NaOH solution (reference). Relative quantum yields of the samples (QY s ) were calculated using Equation 2, [33] …”

Polyaniline/ZnO Hybrid Nanocomposite: Morphology, Spectroscopy and Optimization of ZnO Concentration for Photovoltaic Applications

“…Recently, hybrid polymer–inorganic nanocomposite-based solar cells have attained a PCE of 12% [ 11 ]. Furthermore, organic solar cells made of conjugated polymers and metal oxide semiconductors, such as TiO 2 , ZnO, SnO 2 , etc., are capable of superfast photo-induced charge transfer [ 12 , 13 ], as compared to individual materials [ 14 ].…”